Recent increases in miniaturization, lighter weights, and reduced power consumption in electronic devices have, along with increases in battery capacities, led to a proliferation of battery-powered electronic devices. There has also been an increase in usage systems where data communication is carried out wirelessly between devices at close range. In light of such circumstances, power supply techniques for supplying power at close ranges are also garnering attention.
For example, a conventional non-contact charging system such as that disclosed in Japanese Unexamined Patent Application Publication No. 2008-206327 is constituted by a power transmitter including a primary-side coil in a charging platform or the like and a mobile electronic device including a secondary coil and a charging-type battery, and a user places the mobile electronic device on the power transmitter. Through this, the primary coil of the power transmitter and the secondary coil of the mobile electronic device undergo electromagnetic inductive coupling (magnetic field coupling), and power is supplied to the device being charged so as to charge a secondary battery.